Showing papers by "Georgetown University published in 1978"
TL;DR: The symbiotic theory of cellular evolution is considered the most probable because it holds that organelles, e.g., mitochondria and chloroplasts invaded larger bodies, and combined functions to form eucaryotic cells.
Abstract: A computer branching model is used to analyze cellular evolution. Attention is given to certain key amino acids and nucleotide residues (ferredoxin, 5s ribosomal RNA, and c-type cytochromes) because of their commonality over a wide variety of cell types. Each amino acid or nucleotide residue is a sequence in an inherited biological trait; and the branching method is employed to align sequences so that changes reflect substitution of one residue for another. Based on the computer analysis, the symbiotic theory of cellular evolution is considered the most probable. This theory holds that organelles, e.g., mitochondria and chloroplasts invaded larger bodies, e.g., bacteria, and combined functions to form eucaryotic cells.
505 citations
TL;DR: The [14C] deoxyglucose method for quantitative determination of local cerebral glucose utilization was extended to the macaque monkey and the necessary constants required by its operational equation were evaluated.
Abstract: The [14C]deoxyglucose method for quantitative determination of local cerebral glucose utilization was extended to the macaque monkey. The necessary constants required by its operational equation were evaluated. The lumped constant, measured in 7 normal conscious monkeys, was found to equal 0.344 (SEM, +/- 0.036). The rate constants were also estimated and found to be very similar to those obtained previously in the rat. With these essential constants evaluated, the method was applied to normal conscious monkeys. Local cerebral glucose utilization was found to vary marked throughout the brain but to fall within two distributions, a higher one in gray matter and lower one in white matter. In general, the values fell in a range to be expected from previous measurements of average energy metabolism in the brain as a whole. The values were considerably lower than those observed previously in the conscious rat. Marked heterogeneity of rates of glucose utilization were observed in a number of anatomical structures. In some cases the patterns of heterogeneity were consistent with known histological cytoarchitecture; in others the heterogeneity did not conform with known cytoarchitectural features but corresponded to patterns previously demonstrated by electrophysiological techniques. Many of the regions of the cerebral cortex showed columnar patterns of distribution of higher and lower rates of glucose utilization. These may be a metabolic reflection of the columnar organization of function within the cerebral cortex.
254 citations
TL;DR: Chitin synthesis was studied in both yeast and hyphae of the dimorphic fungus Candida albicans, and enzyme activity was found to be located on the inner side of the plasma membrane.
Abstract: Chitin synthesis was studied in both yeast and hyphae of the dimorphic fungus Candida albicans. Incorporation of N-acetyl-d-[1-(3)H]glucosamine ([(3)H]GluNAc) into an acid-alkali-insoluble fraction was 10 times greater in hyphal-phase cells. A crude preparation of chitin synthetase was obtained from sonically treated protoplasts of both forms of Candida. Enzyme activity, which was determined by using [(14)C]UDP-GLuNAc as a substrate, was exclusively associated with the 80,000 x g pellet from sonically treated protoplasts of both forms. It was determined that enzyme activity (nanomoles of [(14)C]UDP-GluNAc incorporated per milligram of protein) was approximately 2 times greater in hyphae versus yeast cells. Enzyme activity in both yeast and hyphae increased six- to sevenfold when the enzyme preparations were preincubated with trypsin. A vacuolar fraction, obtained from yeast cells but not from hyphae, stimulated enzyme activity when incubated with either yeast or hyphal enzyme preparations. Membrane fractions from protoplasts coated with [(3)H]concanavalin A before disruption were isolated by Renografin density gradient centrifugation. Chitin synthetase activity was preferentially associated with the concanavalin A-labeled fraction, suggesting that the enzyme was located on the plasma membrane. In addition, enzyme activity in protoplasts treated with cold glutaraldehyde before disruption was significantly greater than in protoplasts that were sonically disrupted and then treated with cold glutaraldehyde, indicating that the enzyme resides on the inner side of the plasma membrane.
187 citations
TL;DR: The pathophysiology of mitral valve prolapse and increased systolic left ventricular function in polymyositis remains uncertain; however, the spectrum of cardiac abnormalities, detected noninvasively in 16 of 21 patients (76 percent) may represent a high frequency rate of cardiac involvement in this disease.
Abstract: Twenty-one patients with polymyositis were prospectively examined with echocardiography, phonocardiography and electrocardiography. Cardiac performance, estimated with echocardiography, was enhanced, as shown by a significant (P < 0.01) increase In ejection phase indexes of left ventricular function compared with values in a matched control group. Known causes of the high output state, such as anemia or thyrotoxicosis, were not clinically evident. There was no evidence of left ventricular enlargement, left ventricular wall hypertrophy, or left atrial enlargement in the echocardlogram or chest X-ray film. The echocardiogram showed systolic mitral valve prolapse in 11 of 17 patients (65 percent) with an adequately imaged mitral valve; midsystolic cllcks were present in 7 of these. One patient, who did not have prolapse, had echocardiographic evidence of a small pericardial effusion. Electrocardiographic abnormalities were present in 11 of 21 patients (52 percent) and included evidence of atrioventricular conduction disturbances, atrial and ventricular arrhythmias and left atrial abnormality.
The pathophysiology of mitral valve prolapse and increased systolic left ventricular function in polymyositis remains uncertain; however, the spectrum of cardiac abnormalities, detected noninvasively in 16 of 21 of our patients (76 percent) may represent a high frequency rate of cardiac involvement in this disease.
130 citations
TL;DR: In 52 instances using 0.5 ml of 1% lidocaine (Xylocaine) and a 1.2 cm number 27 gauge needle PDNB was successfully and safely introduced with consistent elimination of pain, rendering NC a painless surgical procedure.
123 citations
TL;DR: Tetracycline is effective, well tolerated, easily administered, and should be considered as the initial therapy for malignant pleural effusions requiring pleural sclerosis.
Abstract: Eighteen patients with advanced metastatic malignancy who had 21 pleural effusions requiring sclerosis for control were randomly allocated to intrapleural therapy with tetracycline or quinacrine. Tetracycline produced partial or complete control of the effusion in ten of 12 trials for a median duration of 6 months (range 1.5 to 22 months). Partial or complete control was obtained in nine of ten trials with quinacrine, for a median duration of 3 months (range 1 to 13 months). All complete responders who died achieved control of their effusions until their terminal admissions despite clinical evidence of overt systemic tumor progression in the intervening period. Single-dose tetracycline therapy was accompanied by less fever (p less than 0.04) and less pleuritic pain (p = 0.09) than quinacrine. Tetracycline is effective, well tolerated, easily administered, and should be considered as the initial therapy for malignant pleural effusions requiring pleural sclerosis.
109 citations
TL;DR: It is concluded that major surgical repair for esophageal perforation is often unnecessary and has the additional drawback of sometimes resulting in equally serious secondary procedures.
105 citations
TL;DR: Ten of 23 patients with advanced measurable adenocarcinoma of the pancreas achieved an objective response after treatment with a regimen consisting of streptozotocin, mitomycin‐C and 5‐fluorouracil (SMF), and responding patients have lived significantly longer than patients with progressive disease.
Abstract: Ten of 23 patients with advanced measureable adenocarcinoma of the pancreas achieved an objective response after treatment with a regimen consisting of streptozotocin, mitomycin-C and 5-fluorouracil (SMF). The median duration of response is in excess of 7 months and responding patients have lived significantly longer than patients with progressive disease (7.5 + months vs. 3 months). The SMF regimen was adequately tolerated. Principal toxicities included myelosuppression, which was generally mild, nausea and vomiting. There was reversible nephrotoxicity in the form of proteinuria in 30% of patients and persistent axotemia in 9% of patients.
102 citations
TL;DR: In this article, the authors developed and presented new approaches to optimal control problems for which the state evolution equation is nonlinear and used ideas from differential geometry and Lie theory to obtain explicit closed-form solutions.
Abstract: It is the purpose of this paper to develop and present new approaches to optimal control problems for which the state evolution equation is nonlinear. For bilinear systems in which the evolution equation is right invariant, it is possible to use ideas from differential geometry and Lie theory to obtain explicit closed-form solutions.
93 citations
TL;DR: Cinnamomum zeylanicum, Nees in Wall is one of the world's oldest spices and form the basis of a variety of synthetically derived chemicals used in the food and cosmetic industries.
Abstract: Cinnamon (Cinnamomum zeylanicum, Nees in Wall) is one of the world's oldest spices. Sri Lanka is the main provider of cinnamon, mainly exported as "cinnamon quills." From a phytochemical viewpoint, cinnamon is q uniquely interesting plant. The volatile oils obtained from the bark, leaf, and root bark vary significantly in chemical composition. Each oil has a different primary constituent: cinnamaldehyde (in the bark oil), eugenol (in the leaf oil), and camphor (in the root-bark oil). Recent studies based on techniques such as gas-liquid chromatography and infrared spectrometry have revealed that the three oils possess the same array of monoterpene hydrocarbons in different proportions. Both gas-liquid chromatography and quantitative infrared spectrometry have recently been used to study changes in the chemical composition in the volatiles of cultivated and wild-growing cinnamons. As a result, some interesting biosynthetic speculations have evolved, and reliable methods of analytical assessment of quality have been developed. The technology of production of cinnamon oils has varied little from the methods introduced by the early Dutch settlers. They are based on variations on the general theme of steam distillation. Recently, new still designs have greatly enhanced the technological capability in Sri Lanka. Cinnamon bark and leaf oils form the basis of a variety of synthetically derived chemicals used in the food and cosmetic industries.
88 citations
TL;DR: It is suggested that the auditory systems in at least several teleost species are well adapted for temporal analysis of acoustic signals, in accordance with recent observations that the temporal rather than the spectral patterns of teleost sounds are significant for communication.
Abstract: Morphological, behavior, and physiological data indicate that there is considerable interspecific variation in auditory function among the more than 20 000 teleost species. This variation includes mechanisms for sound reception, pathways of sound conduction to the ear, excitation patterns within the ear, and possibly, the mechanisms for information processing by the auditory nerve and central nervous system. Although it is still difficult to understand hearing function in terms of our present conceptions of the underlying physiology and structure, it is becoming clear from limited behavioral and physiological data that the auditory systems in at least several teleost species are well adapted for temporal analysis of acoustic signals. This suggestion is in accordance with recent observations that the temporal rather than the spectral patterns of teleost sounds are significant for communication. [Work supported by grants from NIH and NSF to ANP and NSF to RRF.]
TL;DR: Autoradiographic representation of the local rates of cerebral glucose utilization and local cerebral functional activity by means of the [14C]deoxyglucose technique reveals the existence of the ocular dominance columns in the striates of the monkey in the first day of life.
Abstract: Autoradiographic representation of the local rates of cerebral glucose utilization and local cerebral functional activity by means of the [14C]deoxyglucose technique reveals the existence of the ocular dominance columns in the striate cortex of the monkey in the first day of life In contrast to the stability of these columns in more mature brain, monocular deprivation for 3 months from the first day of life results in their complete disappearance and a reversion of the autoradiographic pattern to that seen in animals with normal binocular vision These results are consistent with a reorganization of the representation of the visual fields of the two eyes in the striate cortex and provide additional evidence of the plasticity of the striate cortex of the monkey in early life
TL;DR: The results presented are in close agreement with those previously reported for Ia-bearing Langerhans cells in human and guinea pig epidermis.
Abstract: Immunofluorescent and immunoelectron-microscopic staining methods were utilized to investigate the localization of Ia antigens in murine keratinizing epithelia. Approximately 3–5% of epidermal cells were shown to be Ia positive. Only dendritic Langerhans cells in the interfollicular epidermis and outer root sheaths were found to express Ia antigens. These Ia determinants were shown to be controlled by both theI- A andI- EC subregions of theH-2 complex. The results were confirmed by identifying positively stained cells containing Langerhans cell granules at the ultrastructural level. No staining was noted on the surface of keratinocytes, melanocytes, or immigrant lymphocytes. The results presented are in close agreement with those previously reported for Ia-bearing Langerhans cells in human and guinea pig epidermis.
Patent•
26 Jul 1978TL;DR: In this paper, a semi-rigid polyethylene pipe is used to line pipelines and passageways of long length by extruding the lining tube on site, deflecting the tube so that it is deflected into smaller diametral size, holding the tube in deflected condition, feeding the deflected and held tube into the passageway to be lined.
Abstract: The invention permits the lining of a passageway or pipeline with a resilient but robust, semi-rigid plastics pipe. The invention enables the lining of pipelines and passageways of long length by extruding the lining tube on site, deflecting the tube so that it is deflected into smaller diametral size, holding the tube in the deflected condition, feeding the deflected and held tube into the passageway to be lined, and releasing the hold on the tube so that it deflects or is deflected back to its original form and lines the pipeline or passageway.
TL;DR: Candida albicans endocarditis was established in rabbits after transaortic catherization and vegetations composed of these same host components were observed on the heart valves, although Candida cells were not demonstrable on the valve or vegetation surface.
Abstract: Candida albicans endocarditis was established in rabbits after transaortic catherization. Within 30 to 90 min after infection, C. albicans was observed by scanning electron microscopy on the valve surface. The organisms were predominantly associated with host deposits of erythrocytes, phagocytes, platelets, and fibrinous-appearing material, which collectively appeared on the valve surface in response to trauma. Within 48 h after infection, vegetations composed of these same host components were observed on the heart valves, although Candida cells were not demonstrable on the valve or vegetation surface. When the vegetations were examined by transmission electron microscopy, Candida blastospores were only observed within phagocytic cells (predominantly monocytes) enmeshed within the vegetation matrix. Many of the intracellular organisms were undergoing degradation, as evidenced by a reduction in electron density of the cell wall. Other fungi had highly electron-dense cell walls and germ tubes. Phagocytic cells containing germinating Candida were highly vacuolated and were observed at various stages of cell lysis. After 7 days of infection, the vegetation contained a dense meshwork of fibrin and Candida pseudohyphae with 108 to 109 colony-forming units/g of vegetation. The mature vegetation was devoid of phagocytic cells and continued to grow until the death of the animal. Images
TL;DR: The data demonstrate that the peak tumor FdUMP concentration and the kinetics of its clearance correlated with the responsiveness of the two specific murine tumors to 5-FU, and should be tested for its potential clinical application as a means of selecting patients with gastrointestinal and breast cancer to be treated with this agent.
TL;DR: In this article, Hemoperfusion in Drug Intoxication: Clinical and Laboratory Aspects, a review of Hemoprocession in Drug Metabolism Reviews: Vol. 8, No. 1, pp. 69-104.
Abstract: (1978). Hemoperfusion in Drug Intoxication: Clinical and Laboratory Aspects. Drug Metabolism Reviews: Vol. 8, No. 1, pp. 69-104.
TL;DR: A young female with inflammatory bowel disease who developed severe hepatotoxicity as part of a systemic hypersensitivity reaction to sulfasalazine is reported, indicating the serious nature of the illness.
TL;DR: O'Connor as mentioned in this paper argued that a nation ought not to violate a principle of just warfare unless a more important principle takes precedence, but he did not show how the principles of just war are themselves derivative from certain prima-facie moral obligations.
Abstract: moral obligations. Thus, a nation ought not to violate a principle of just warfare unless a more important principle takes precedence." O'Connor does not, however, try to show how the principles of just warfare are themselves derivative from certain prima-facie
TL;DR: A hormonal interrelationship is suggested between breast cancer and meningioma and the knowledge of this potential association is important in the interpretation and treatment of patients with breast cancer who develop central nervous system manifestations.
Abstract: We report two cases of breast cancer in whom meningioma subsequently developed and provide a brief review of the literature. A hormonal interrelationship is suggested. The knowledge of this potential association is important in the interpretation and treatment of patients with breast cancer who develop central nervous system manifestations. Cancer 42:1992-1994, 1978.
TL;DR: A patient with acute myelomonocytic leukemia and multiple myeloma occurring simultaneously prior to initiation of chemotherapy is described and mechanisms for this occurrence are discussed.
Abstract: A patient with acute myelomonocytic leukemia and multiple myeloma occurring simultaneously prior to initiation of chemotherapy is described. Possible mechanisms for this occurrence are discussed.
TL;DR: The data suggest a relationship between ADP-ribosylation and chromatin organization and vice versa and a decline and stabilization of specific activity is noted.
Abstract: Poly (ADP-ribose) polymerase, a nuclear protein-modifying enzyme, binds to the internucleosomal linker region of chromatin, although it modifies certain core nucleosomal histones in addition to histone H1. The activity per unit of DNA chromatin changes with the nucleosome repeat number. It reaches a maximum on chromatin of 8-10 nucleosomes in length. As the complexity of chromatin with respect to nucleosome repeat number and compactness increases, a decline and stabilization of specific activity is noted. The difference in specific activity is maintained through resedimentation and dialysis of particles. It does not appear due to differences in polymer chain length or differential degradation of poly (ADP-ribose). The data suggest a relationship between ADP-ribosylation and chromatin organization and vice versa.
TL;DR: The results suggest that lingual lipase is produced prenatally by the demilune cells of the lingual mucous glands and postnatally predominately by the lingUAL serous glands.
TL;DR: It is suggested that circulating triglyceride-fatty acids are used by the fetal lung for surfactant synthesis and suggests that lipoprotein lipase may play a role in the growth and maturation of individual organs.
Abstract: Summary: Lipoprotein lipase activity in lung and heart was studied in fetal (17-22 days of gestation) and newborn rats from the day of birth until 30 days of age. Enzyme activity in epididymal, omental, and parametrial adipose tissue was tested after 18 days of age. Blood triglyceride levels were measured at all ages from 17 days in utero until 30 days after birth. The developmental pattern of lipoprotein lipase differed markedly in lung and heart. Although lipoprotein lipase activity was 4 to 5 times higher hi adult rat heart than in lung (30-40 U/g in heart vs. 8-11 U/g in lung), the activity was almost completely absent from fetal heart and was very low during the first 3 days after birth. Lipoprotein lipase reached 60-70% of adult activity at 6 days and remained at that level until 19 days after birth; adult activity levels were reached at 24 days. In the lung, contrary to the heart, lipoprotein lipase activity was high in the fetus (84% of adult activity), decreased immediately after birth to 45% of adult activity at 2 days, and remained at that level up to 15 days after birth. Enzyme activity started to rise again at 15 days and reached adult levels at 21 days of age. Adipose tissue was present in trace amounts before the age of 2 weeks. In the three fat depots tested, lipoprotein lipase activity was 50% lower than in adults between 20 and 30 days after birth. Blood triglyceride levels increased 4- fold between 2 to 10 hr after birth and remained elevated during the first 3 days after birth. Speculation: The triglyceridemia that starts in the immediate postnatal period and lasts for several days in the rat probably results from the combination of high fat intake and low clearing ability of the extrahepatic tissues. In addition to its role in clearing circulating triglyceride, lipoprotein lipase may play a role in the growth and maturation of individual organs. The present study shows that lipoprotein lipase activity is high in fetal lung during the period of marked surfactant synthesis and suggests that circulating triglyceride-fatty acids are used by the fetal lung for surfactant synthesis.
TL;DR: It is concluded that liquid-crystal thermometers may adequately serve as screening devices for intraoperative hyperthermia.
Abstract: Disposable liquid-crystal temperature-trend indicators were evaluated under clinical conditions that simulated the development of intraoperative hyperthermia during anesthesia. Comparison was made to forehead thermistors for rapidity, accuracy, and linearity of response as well as correlation with esophageal and rectal thermistor recordings. The liquid-crystal monitors were comparable to the forehead thermistors in both rapidity and linearity or response, but not in accuracy. A linear correlation existed with the esophageal thermistor temperatures. Correlation with the rectal temperatures was not as exact. It is concluded that liquid-crystal thermometers may adequately serve as screening devices for intraoperative hyperthermia.